1. Field of the Invention
The present invention relates to a method for making 4-oxo-4-((4-(phenylamino)phenyl)amino)-2-butenoic acid.
2. Background of the Art
4-Oxo-4-((4-(phenylamino)phenyl)amino)-2-butenoic acid is used in preparing high performance dispersants for lubricants. This material has very limited solubility in common organic solvents such as acetone, methylethyl ketone (MEK), methyl isobutyl ketone, ethyl acetate, butyl acetate, xylene, toluene, N-methylpyrrolidinone, and the like. The grafting process for preparing a lubricant dispersant from this compound does not lend itself well to processing volatile carrier solvents. At best, only about 30% to 40% by weight of butenoic acid can be loaded into the strongest solvents, and the use of volatile organic solvents also introduces hazards during the customers' use of the product.
What is needed is a process for making this compound that does not introduce volatile organic solvent in the final product.